Use fastGetAttribute in more places

Source/core/html/HTMLInputElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Samsung Electronics. All rights reserved.
@@ skipping 787 matching lines @@
 }
 
 String HTMLInputElement::altText() const
 {
     // http://www.w3.org/TR/1998/REC-html40-19980424/appendix/notes.html#altgen
     // also heavily discussed by Hixie on bugzilla
     // note this is intentionally different to HTMLImageElement::altText()
     String alt = fastGetAttribute(altAttr);
     // fall back to title attribute
     if (alt.isNull())
-        alt = getAttribute(titleAttr);
+        alt = fastGetAttribute(titleAttr);
     if (alt.isNull())
-        alt = getAttribute(valueAttr);
+        alt = fastGetAttribute(valueAttr);
     if (alt.isEmpty())
         alt = locale().queryString(blink::WebLocalizedString::InputElementAltText);
     return alt;
 }
 
 bool HTMLInputElement::canBeSuccessfulSubmitButton() const
 {
     return m_inputType->canBeSuccessfulSubmitButton();
 }
 
@@ skipping 1051 matching lines @@
 }
 
 #if ENABLE(INPUT_MULTIPLE_FIELDS_UI)
 PassRefPtr<RenderStyle> HTMLInputElement::customStyleForRenderer()
 {
     return m_inputTypeView->customStyleForRenderer(originalStyleForRenderer());
 }
 #endif
 
 } // namespace